MongoDB vs RocksDB: What are the differences?

Key Differences between MongoDB and RocksDB

MongoDB and RocksDB are two popular databases with significant differences in terms of their features and usage.

1. Data Structure: MongoDB is a document-oriented database, where data is stored in JSON-like documents with dynamic schemas. RocksDB, on the other hand, is a key-value store designed for persistence on flash or disk storage. It stores data in a hierarchical structure, with keys and values associated with each other.

2. Scalability: MongoDB is designed for horizontal scalability, allowing you to distribute data across multiple servers and scale your application as needed. RocksDB, however, is primarily designed for single-node deployments and is not natively built for distributed computing.

3. Query Language: MongoDB uses a powerful query language called MongoDB Query Language (MQL), which allows you to perform complex queries, aggregations, and transformations on the data. RocksDB, being a key-value store, does not have an in-built query language and typically relies on external processing tools for data analysis.

4. Transactions: MongoDB offers multi-document transactions, which allow you to perform multiple operations on multiple documents in a single atomic unit. RocksDB, on the other hand, does not natively support transactions and is mainly focused on fast key-value operations.

5. Indexing: MongoDB provides flexible indexing options, including single-field and multi-field indexes, geospatial indexes, and text indexes, to improve query performance. RocksDB, being a key-value store, does not support complex indexing mechanisms and primarily relies on simple key-based lookups.

6. Use Cases: MongoDB is suitable for a wide range of use cases that require flexible data modeling, real-time analytics, and horizontal scalability, such as content management systems, social media applications, and e-commerce platforms. RocksDB, on the other hand, is well-suited for low-latency and high-throughput applications that require fast read and write operations, such as cache layers, message queues, and transaction logs.

In summary, MongoDB is a document-oriented database designed for flexible data modeling and horizontal scalability, while RocksDB is a key-value store optimized for low-latency and high-throughput single-node deployments.